Electronic and optical competence of TiO2/BiVO4 nanocomposites in the photocatalytic processes.

Nanocomposites with different ratios of titanium dioxide and bismuth vanadate [TiO2]/[BiVO4] give rise to compatible electronic band structure alignment at their interfaces to ensure enhanced photoactivated charge transfer under visible light. The sol-gel method and suitable post-synthesis thermal treatments were used to synthesize different compositions with stabilized anatase phase of TiO2 and monoclinic scheelite polymorph BiVO4. Structural, electronic and optical characterizations were performed and the results were analysed as a function of the stoichiometry, in which both crystalline structures show a clear junction formation among their characteristic stacking planes. Photocatalytic and (photo) electrochemical responses of the nanocomposites were investigated and tested for the degradation of azo dyes (Acid Blue-113, AB-113) (~ 99%) under visible light radiation. The nanocomposite with a mass ratio of (1:10) shows the highest photocatalytic efficiency compared to the other compositions. HRTEM images showed marked regions in which both crystalline structures form a clear junction and their characteristic planes. However, the increase of BiVO4 content in the network overcomes the photocatalytic activity due to the decrease in the reduction potential of the photo-generated electrons with high recombination rates.

The effects of severe plastic deformation on the mechanical and corrosion characteristics of a bioresorbable Mg-ZKQX6000 alloy.

In this work, a bioresorbable Mg-ZKQX6000 (Mg-6Zn-0.6Zr-0.4Ag-0.2Ca (wt%)) alloy was severely plastically deformed via equal channel angular pressing (ECAP) according to three unique hybrid routes at low temperatures (200 °C to 125 °C). The roles of ECAP processing on microstructure, and ensuing mechanical properties and corrosion rates, are assessed. Microstructurally, ECAP induces a complex plethora of features, especially variations in grain sizes and precipitates' sizes, distributions, and morphologies for individual cases. Mechanically, ECAP generally refined grain size, resulting in ultra-high strength levels of about 400 MPa in ultimate tensile strength for several cases; however, deformation via ECAP of precipitates induced embrittlement and low elongation to failure levels. Corrosion testing, conducted in simulated bodily fluid at bodily pH levels to mimic conditions in the human body, revealed consistent corrosion rates across several techniques (mass loss, hydrogen evolution, and electrochemical impedance spectroscopy (EIS)), showing that severe plastic deformation deteriorates corrosion resistance for this material. In-situ corrosion monitoring explained that corrosion accelerated after ECAP due to the creation of heterogeneous, anodic shear zones, which exhibited dense regions of refined grains and fine precipitates. Suggestions for future design and thermomechanical processing of Mg alloys for bioresorbable orthopedic implants are provided.

Medical management of snake bite in a dog caused by Bothrops asper: case report¤ / Manejo médico de un accidente ofídico en un perro causado por Bothrops asper: reporte de caso / Manejo medico de um acidente ofídico em um cachorro causado por Bothrops asper: relato de caso

In Colombia the incidence of ophidic accidents and its treatment in animals is rarely documentes which negatively affects its prognosis. A case is described of a German Sheperd with antecedent of a snake bite by Bothrops asper in the right infra-orbitary region which ocurred approximately 12 hours before consultation. To physical examination bilateral inflammation of the facial soft tissues and bleeding through the bite site were evidenced. After evaluating the anamnesic and the results of clinical and paraclinical exams the final diagnosis was moderate bothropic accident. Medical management consisted in administration of antiophidic serum, after which the patient showed favorable clinical evolution aproximately eight hours after treatment was established, being released two days after coming into the clinic. In this report the medical management established and the clinical evolution of the pacient are described.

En Colombia la incidencia del accidente ofídico y su tratamiento en animales está escasamente documentado lo que afecta negativamente su pronóstico. Se describe el caso de un Pastor alemán con antecedente de mordedura por Bothrops asper en la región infraorbital derecha ocurrida aproximadamente 12 horas antes de la consulta. Al examen físico se evidenció una inflamación bilateral de tejidos blandos faciales, y un sangrado a través del sitio de la mordedura. Después de evaluar los anamnésicos y los resultados de los exámenes clínico y paraclínicos el diagnóstico final fue accidente Bothrópico moderado. El manejo médico consistió en la administración de suero antiofídico ante lo cual el paciente mostro evolución clínica favorable, aproximadamente ocho horas después de instaurado el tratamiento, siendo dado de alta dos días después de ingresado a la clínica. En este reporte se describe el manejo médico instaurado y la evolución clínica del paciente.

Na Colômbia, a incidência de picadas de cobra e o tratamento dos animais domésticos é pouco conhecida, o que afeta negativamente o prognóstico desse tipo de acidente. Descreve-se o caso de um pastor alemão com uma história de mordida de cobra venenosa (Bothrops asper) na região infraorbitária direita ocorrida cerca de 12 horas antes da consulta medica. Ao exame físico, evidenciou-se inflamação bilateral do tecido mole facial e sangramento evidenciado através do lugar da mordida. Depois de avaliar os anamnésicos e os resultados dos exames clínicos e paraclínicos, o diagnóstico final foi mordida botrópica moderada. O manejo médico consistiu na administração de soro antiofídico, depois disto, o paciente apresentou evolução clínica favorável após oito horas de começado o tratamento. O cachorro recebeu a alta medica dois dias depois. Neste relatório, descreve-se o manejo medico instaurado e a evolução clínica do paciente

BET differences among simultaneous evoked frequency band responses during early-stage visual processing distinguish schizophrenia from healthy subjects.

In this work, we attempt to extend to the schizophrenia's research the evidence that different frequency bands may emerge from different sources during early-stage visual processing, in a mental state-specific manner, while subjects are passively viewing a visual stimulus. We applied standard pattern reversal stimulation (checker-board), a task with low cognitive demands, coupled to a dense EEG recording system to estimate the neural correlates of the evoked theta, alpha, beta, beta1, and gamma frequency band responses by means of brain electrical tomography (BET). After filtering the evoked activity using different band-passes, a very different picture about the current sources during P100 will emerge. The results showed notable differences between the two groups. In healthy subjects we localized the significances in the anterior cingulate, caudate nucleus, thalamus, precuneous region, and superior parietal that were more active for gamma band. In patients with schizophrenia differences occupy the hippocampus, parahippocampus, thalamus, midbrain, precuneus, and superior parietal regions. Most areas were more active for gamma band except precuneous and superior parietal region more active for theta and alpha frequency band. These sets of regions, in both groups, reflect events that are parallel to and partly independent of the P100 component, while in the schizophrenia, these regions have been previous linked to the major symptoms of the disease. We concluded that this result provides important evidence indicating that the proposed method is able to differentiate electrophysiological patterns in healthy subjects from those in patients with schizophrenia.

Las prostaglandinas: un nuevo enfoque en la terapeutica de la enfermedad acido-peptica / Prostaglandins: a new approach in the treatment of acid-peptic disease

Despues de su descubrimiento hace 30 anos, las PG han sido objeto de multiples trabajos por diversos grupos de experimentacion, permitiendo un mejor conocimiento de los mecanismos biologicos en los cuales se involucran estas sustancias. Mas recientemente se ha superado una nueva etapa en la sintesis de las sustancias analogas a las PG, abriendo el horizonte de una terapeutica nueva, la cual estriba en la utilizacion de mecanismos de accion proximos a la actividad fisiologica del organismo. En esta forma podemos enunciar las premisas de una nueva era terapeutica como testimonio de las primeras aplicaciones en el tratamiento de la enfermedad ulcerosa

Population genetics in the American Tropics : 18. The genetic structure of peripheral Drosophila pseudoobscura from Colombia.

There are several Colombian populations of Drosophila pseudoobscura which have begun to show divergence. The temporal samples of Torobarroso, one of the local populations identified, demonstrate genetic "resourcefulness" and selective opportunism by fluctuating mortality. The data suggest that both balanced selection and mutational origin are necessary to account for the frequencies of drastic genes encountered. In genetic isolates there seems to exist alternatively a mutational component and a balanced - selection component. These components overcome the damage in the first instance and in the second instance, profit from the recessive load.